MAX6692MUA Maxim Integrated Products, MAX6692MUA Datasheet - Page 14

• Manufacturer Part Number: MAX6692MUA
• Description: Board Mount Temperature Sensors
• Manufacturer: Maxim Integrated Products

Specifications of MAX6692MUA

• Full Temp Accuracy: +/- 3 C
• Package / Case: uSOP
• Digital Output - Bus Interface: Serial (2-Wire)
• Digital Output - Number Of Bits: 10 bit + Sign
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: 0 C
• Output Type: Digital
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Precision SMBus-Compatible Remote/Local
Temperature Sensors with Overtemperature Alarms
When sensing local temperature, these devices are
intended to measure the temperature of the PCB to
which they are soldered. The leads provide a good ther-
mal path between the PCB traces and the die. Thermal
conductivity between the die and the ambient air is poor
by comparison, making air temperature measurements
impractical. Because the thermal mass of the PCB is far
greater than that of the MAX6648/MAX6692, the devices
follow temperature changes on the PCB with little or no
perceivable delay.
When measuring the temperature of a CPU or other IC
with an on-chip sense junction, thermal mass has virtu-
ally no effect; the measured temperature of the junction
tracks the actual temperature within a conversion cycle.
When measuring temperature with discrete remote sen-
sors, smaller packages, such as SOT23s, yield the best
thermal response times. Take care to account for ther-
mal gradients between the heat source and the sensor,
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OVERT
ALERT
DXN
DXP
Thermal Mass and Self-Heating
V
CC
Q
Q
R
R
S
S
DIODE
FAULT
LOCAL
REMOTE
MUX
ALERT RESPONSE ADDRESS
REMOTE TEMPERATURE
LOCAL TEMPERATURE
OVERT THRESHOLD
ALERT THRESHOLD
REGISTER BANK
COMMAND BYTE
and ensure that stray air currents across the sensor
package do not interfere with measurement accuracy.
Self-heating does not significantly affect measurement
accuracy. Remote-sensor self-heating due to the diode
current source is negligible. For the local diode, the
worst-case error occurs when autoconverting at the
fastest rate and simultaneously sinking maximum current
at the ALERT output. For example, with V
4Hz conversion rate and with ALERT sinking 1mA, the
typical power dissipation is:
θ
so assuming no copper PCB heat sinking, the resulting
temperature rise is:
Even under nearly worst-case conditions, it is difficult to
introduce a significant self-heating error.
J-A
ADC
for the 8-pin µMAX package is about +221°C/W,
ΔT = 2.9mW x (+221°C/W) = +0.6409°C
5.0V x 500µA + 0.4V x 1mA = 2.9mW
8
8
MAX6648
MAX6692
READ
7
WRITE
CONTROL
ADDRESS
DECODER
SMBus
LOGIC
Functional Diagram
2
SMBDATA
SMBCLK
CC
= 5.0V, at a